So in this module, we're going to talk about the diseases that we see in disaster situation and humanitarian crisis. We're going to look at the communicable diseases which are common in displaced populations. And to talk about some of the common prevention. And some of the common control methods and measures that can be used. We'll talk about why the epidemiological transitions has changed the types of diseases that we see and that we have to deal with. And we'll also talk about how responding to humanitarian crises in middle-income countries is different because now we'll have to look at both issues of communicable diseases and non-communicable disease, both of which we'll discuss in this module. Here, we see the epidemiological transition and this shows that over time and this is decades and sometimes even centuries, we see a gradual decline in communicable diseases in the country and at the same time with the development of the country and as lifestyles change we see a rise in the non-communicable diseases. But it's important to point out the communicable diseases in that pattern does not disappear completely. So even if you're a highly developed country, you can still deal with problems such as HIV and Zika and so forth. But in between, we have something known as the transition trap and this is where these two trends cover each other, where the rising number of non-communicable diseases crosses the decreasing number of communicable diseases. And here, we have a problem because we're dealing with a population with a country which contains both of these trends. So we can't set aside the extreme vigilance that many countries have to maintain to handle outbreaks of communicable diseases. And at the same time, we have to alter our services and alter our way of thinking, to start encompassing some of the lifestyle diseases, some of the diseases that traditionally are associated with more affluent societies. So that burden is shifting. So we see a shift from the traditional communicable diseases of cholera, diarrhea, measles, malaria, lice and scabies. Toward the non-communicable issues such as hypertension, diabetes particularly type 2 diabetes, respiratory infections, mental health issues, and malignancies. So now, I want to talk about the communicable diseases specifically. We can say that communicable diseases are usually the major cause of death in a displaced population particularly in low income countries and often, this occurs in conjunction with malnutrition or these days we would say under nutrition. This is less true in the middle development counties and there, we have problems with over nutrition. If we look at where the death occur, these predominantly occur in the children under age five. And we could even back up and say, these occur in children under age two. These are the high risk children. And these occur in the emergency phase of a disaster. And here, I could just pause for a moment to say, disasters can be divided into the emergency phase and the post-emergency phase. This division is built on death rates and those death rates are twice the underlying death rate for a community. So we can say that when for a particular culture or particular country that death rate has doubled over its pre-disaster number then we can say we're in to the emergency phase. It's really important to have an adequate surveillance system in place so we can see these communicable diseases emerging. If we do not detect these emerging communicable diseases then we can have a major outbreak and we will be behind the curve as it were, we will be under prepared and we will have a difficult time catching up with its impact on the population that we're dealing with. At the same time, we have to be aware that we have emerging diseases. So there are new diseases coming out, and there are endemic diseases that are present, but they're changing in some way, because a population that's affected by disasters is not a normal population. It has increased susceptibilities and increased vulnerabilities, which puts it at risk. Here is the communicable disease cycle. It starts off with a non-disease state, the exposure, a susceptible population, biological manifestation, progression of disease to clinical manifestation, and then one of three things can happen. The disease can progress on to death, if there's no treatment for this condition, or there's not access to treatment. It can progress to a chronic disease or it can spontaneously cure and then the person is returned to the non-disease state. Now, this cycle is very important from the public health aspect. We have a number of preventive measures that we can see on the right-hand side. Reducing its risks, changing the population susceptibility to disease, and some examples of these are such things as safe or adequate water, good sanitation, healthy environment, good access to food, immunizations, good shelter, and of course, health services as well. Then, if we progress, we can look over here in the red circles. The clinical situations and where public health can have an intervention still and these can be in the areas of case finding, they can be in the areas of contract tracing and they can be in the area of case management. Now, just step back a little bit to our Ebola outbreak of a few years back and you can see, those three elements in managing the Ebola outbreak. And those three elements alone were probably responsible for much of the success in eliminating this outbreak. Then, we can look again at the impact of communicable diseases on a population. These conditions can cause fear, they can cause public disorder, they can cause panic. And we remember the panic that Ebola produced. We can remember the panic that Ebola produced in Sierra Leone. And the panic that Ebola produced in Liberia. We can also think about the panic that Ebola produced in New Jersey and the panic that it produced in Texas. So these are conditions that sometimes produce a level of hysteria way beyond their public health consequences. These diseases can cause population movements. Large numbers of people flee in the face of these epidemics at various times, they have major economic consequences. People neglect their regular activity, their business, their agriculture, because they're frightened of things. Or they may be neglecting them as a part of an official policy when we dealt with Ebola in West Africa, many of the markets were closed in order to avoid people intermingling and potentially sharing their infection. Then, we have to think on the individual basis of the disruptive consequences of outbreaks of disease. There's certainly lost of productivity, and there's been many studies of HIV, and the consequences that that had on households. And then, we can just look at the cost of funerals, and in many societies funerals are a very expensive processes. There's a lot of cultural and lot of religious rituals that have to be observed. And many of these are very expensive. So in the population, there's a lot of impact. But on the health system, there's also a lot of impact. And the diseases can overwhelm the capacity of the health system to cope. Other diseases go unattended, and these consequences are much worse if this is in a place where there's no community-based services. Again, if we wanted to spin back a few years to Ebola, we can see how all of these things happen. And probably there was a net increase in all cause mortality during the Ebola outbreak that wasn't due to Ebola, but was due to some of the other diseases that were not attended. We also see that health systems that are weak may collapse and this may be particularly bad where there's been decentralization, and the decentralization really didn't receive much in the way of resources. And that weakened it and it made it less able to cope with whatever this conflict was that occurred. Epidemics, as we say, cause rumors. And these rumors but unrealistic demands on health services. Health services cannot meet these. It depletes supplies very quickly. And health workers are depleted, as well. They may be frightened and they may leave. Or they may have died from the consequence of this outbreak of disease. And to illustrate that, here's a slide that shows the death among Ebola cases in the three countries of West Africa during that outbreak. If we looked at all the people that died from Ebola in West Africa, it's sobering to think 10% of the deaths were among health workers. So this is a consequence for, not only the health system, but for the health workers themselves. And I want to go through a few of the common communicable diseases that might occur in disasters. And there are some that have major epidemic potential and consequences, and we'll revisit a little bit about these later on. But cholera, meningitis, measles, Ebola, and of course, Shigella, are the ones that come to mind to most people, when we think about these epidemic potentials. And here's a publication about the infectious diseases following the aftermath of monsoon flooding in Pakistan. Huge outbreaks of cholera which occurred as a consequence of that. Now, this is a reminder that outbreaks are unlikely after natural disasters. There are some exceptions, and flooding is the most common one. Displacement of population was a common one. Ebola was perhaps not specifically related to natural disasters. This was a consequence of conflict in West Africa, a consequence of weak health systems, of poor governance in some of the countries, which contributed. It's a reminder also that proven systems may have decreased effectiveness in displaced populations and with weak systems. Again, using Ebola, Ebola has been managed quite well with the last two outbreaks in Uganda for various reasons, and partly because the systems in Uganda were much stronger; when the same disease occurred in West Africa, we had different consequences. Then, we have diseases that occur in certain circumstances. Malaria, for instance, Yellow Fever. And not long ago there was a major Yellow Fever outbreak through much of Africa in displaced populations as well as non-displaced populations. There are issues of relapsing fever and hepatitis A and E, which has been an increasing problem. Particularly in the area in Darfur, and other parts of Sudan. This is a map, and this reminds us that certain areas are affected more than other areas. This is a map of hepatitis A and E in various localities in Darfur. Then, there's diseases that are potential, not always going to be there, but are very likely to occur. Sexually transmitted infections, depends on the nature of the population and what's happened to this population. Increasingly, we're seeing outbreaks of scabies and lice. This is particularly a problem of middle income countries. We saw a huge problem with this in the Balkans with the Balkan Wars. We also see this with the displaced population from Syria. HIV in some populations has increased. Some populations are actually spared from HIV. Interesting enough, the conflict in Angola had isolated that country from its neighbors and it's probably also protected them from HIV. Then, we have communicable diseases in children. And we should stop for a moment to say when we're coping with the consequences of communicable diseases, children bear the brunt of this consequence. And commonly, although children under the age of 15 may constitute 30 or 40% of the population, they may be 50 or 60% of the people seeking healthcare in the health facilities. So a majority of illnesses can be caused only by a few conditions which actually makes it easier to deal with a large number of ill children in a busy health service. The majority of deaths, as we mentioned, are among the under five, is particularly among the under two. Illustrated here are our children from displaced families coming from Syria, this was in Lebanon, and you see children in the waiting room, and you see a young child sitting on the doctor's desk in Tyre in Southern Lebanon. Now, one of the ways that we can deal with a small number of diseases in a large population is using a standard algorithm. And here is the integrated management of childhood illness algorithm. And this is for a particular country, and these are adapted for various countries. But this is kind of a paper-based, computerized system to inquire about what's wrong with the child and then follow this pathway to reach the desired or the recommended treatment for that child. This is a way that people with not so much a professional education can do a very competent job in providing care for these large numbers of children.
